miles



J. c. MILES 2,601,314

COAL STOVE 2 SHEETS--SHEET June 24, 1952 Filed June 2, 1947 w ku %7 J. C. MILES COAL STOVE June 24, 1952 2 SHEETS-SHEET 2 Filed June 2, l94'7 Patented June 24, 1952 OFFICE COAL STOVE John 0. Miles, Urbane, lil., assignor to The- University of-'Illinois Foundation, a, nonp'ofitcotporaton of Illinos Appl'cation` June 2, 1947; Serial No. 751 906 2 Claims. v (CI. 126-713) This inventon relates to a coal stove -andpap ti'cularly to acoal stove having aby-pass leading from the fire box of' the stove to an exit for the gases of combustion and' a cooperating door arranged to communicate between'` the. exterior of the stove and the interier of the fire box through the opening that is normally closed bythe bypassdoor. The` ihvention alsorelates to means for opening and closing the doors together( It has been proposed in the pastto provide a by-pass door between thefire: box and the passageway that is provided for the gases ot combustion With thi's door' being capable of being opened prior to the introduction of coal into the fire box. There is aiso provided a door between the exterior of' the stove and the fire box so that fresh coal can be introduced to the fire* box. The by-pass door permits venting of smoky gases in the fire box When the exterior door* is opened for the* introduction of coal or for other' reasons so that these gases Will hot escape to the exterior of' the stove. In the improved Construction, which forms the subject matterof' this invention, the by-pass door andthe exterior door are aligned With each other so that coal may be introduced into` the fire box through the openings normally closed` by' said doors. Means are provided for opening both doors. lt ispreferred' that the doors be so arranged that the by-pass door may be' opened` to` give complete communication between the fire box and the passageway for burnt gases before' the exterior door gives complete communication With the exteror of` the stove. This permits any gases in the fire box to( be Vented to' the gas passageway before these gases have an opportunity to escape through the exterordoor. Means are preferably provided con*- nectirg the doors so that both doors are opened and closed together;

It is preferred that the by*-pass door be arranged'at or'near the top of" the fire boxwith the exterior' door being' arranged adjacent the bypassdoor. This permits the complete filling of the fire box With coal thereby'leaving no' empty space for the accumulation of combustion gases formed in the coking of the coal; This formation of' gases in a pocket in the fire box is eliminated so: as to avoid What is known as "puff back. This is caused by air entering the portion of the fire box occupied by these heated combustion gases and causing mniature explosions. These explosions result in smoke beim forced out into the room.

The invention will be described as related to the embodiments shown in` theaccompanying drawings. Of the drawings: Fig. 1 is a fragmentary vertical section through a stove embodying the invention; Fig. 2 is a f'agmentary elevation of the stove of Fi g. 1 showing the exterior 2` door;;and Fig. 3 is ;a section taken along line 3-3 ofFg..l.

the' embcdiment shown in` Figs. 1, 2 and; 3, tlierstove compriseslan' outer shell lil a fire box Mt. a gratea IZ beneath the fire box, an inclined wal I& defining one. side of the fire box and having; spaced openings !ta therein, a verticalwall M on theopposite side of the fire box and spaced from the outer shell' m: With this Wall also having spac'ed openings' I ia' therein, a steeply inclined Wall lir" at the topofthe fire box formed of fire brickor the like,ta combustiontzone !6 abovethe fire: box; and communicating therewith through relati'vely narrow threat lsa, and a stackt H f or` the exhaust of the'gases of combustion. The bottom off the stove` is provided with an ash receptacle` i'a beneath the grate !2 and this por;- tion of the' stove is` provided with adoor [9 through which thezreceptacle' |8 may be; removed.

The space between:` the* inclined wall li'` and the shell' s of the stove is provided' with-.a'- bame 28' extending from the shell to a point: adjacent the bottom of the Wall` [3: Air' is` adnitted` to the stove through a pair of openings 21: and, 22 in the shell lil? on* either' side of the baffiea 20. These openings` are' arranged sot as' to be opened and clbsed'by a single' d'amper 23 that is mounted on athreadedbolt 2& engaging a hole in theshell HP adjacent the' topi end'. of the bame 20. Air entering the' top'holel fiows through theopen ingsla in the wall' !3- into the fire box.. This air serves as ceking air for the coal in the fire box. Air entering` the bottom hole 22* is* directed downwardly bythe bafiie 29 to theregion: under the grate !2. Some of this airflows 'through the grate l'2- and:` serves as coke-burning air. Another' portionof" the air flows up between` the Vertical Wall' M' and, the shell ID' of the' stove through the openings i a and through the threat Ita into the' combusti'on zone IE". With this arrangement, the'` full supply of air to' the stove' i's controlledby the single damper 23.

Nar thet'op of the' fire box H thereis' located aby-pass door Zecommunicatingbetween the top of `the-fire box` and the passageway 26 for gases ot'combustion; As shown in Fig. l this passageway isthe entire top of the stove. This top portion of the stove is lined with fire brick 21 or the like andis providedwith an outwardly extending bafii'e- 2321; also of fire brick, on the side` of` the stoveopposite the location of the by-pass'door'ZS. The gases of combuston leaving the combusti'on zone' i i aredi'rected by the baffie Z-la toward" the other side-of the stove and then backup through the' stack I? that is located immediately above the hame ilb. When the by-pass door 25` is opened, any gases in the fire box ll are vented to the passageway 26. The amount of gases in the fire box will be quite small, however, .as the ;fire box is ordinarily kept almost completely filled with coal.

Located adjacent the by-pass door is an exterior door 28 communicating with the exterior of the stove. The by-pass door 25 is hingedly mounted on the exterior door 28 by providing a pair of spaced brackets 25a formed integrally with the by-pass door 25 and extending toward the exterior door 28. These brackets have their outer ends attached by a hinge 29 to the exterior door 28. This hinge is substantially horizontal. Rigidly mounted on the hinge 29 is an Operating arm 30 extending through the exterior door 28 and having its outer end :lila exten-ding upwardly. This outer end is provided with a hand-engageable portion 391) of coiled wire.

The exterior door 28 is hingedly mounted on the shell m of the stove by means of a vertical hinge 3! mounted on a door rame 32. When it is desired to introduce coal into the fire box ll, the Operating arm is turned so that its outer end 39a is pointed outwardly. This turns the by-pass door 2'5 up against the exterior door 28 and to the position shown in dotted lines in Fig. 1. Both the by-pass door 25 and the exterior door 28 may then be opened around the hinge 3l upon which the exterior door is mounted. Coal may then be introduced into the fire box through the openings normally closed by the doors 25 and 28. Means are preferably provided for releasably retaining the by-pass door 25 in a position against the exterior door 28. As shown, this means may comprise a spring-pressed ball 33 in the top of the exterior door'23. With this arrangement, the by-pass door may be released either by jarring the exterior door 23 against its frame or by turning the Operating arm 39.

The top edge 25b of the by-pass door 25 is inclined so as to seat against an inclined surface on a frame member 34 located at the top of the fire box I l. The sides of the by-pass door 25 'seat on raised portions sda on the rame member 34 so that the sides of the by-pass door may be spaced inwardly and not scrape side flanges 341) that connect the exterior door rame 32 and the interior frame 34. The bottom edge of the bypass door 25 seats against the bottom of the inner frame 34 as shown in Fig. 1.

With the arrangement just described, coal may be fed through the by-pass door 25 so that the fire box l I may be substantially completely filled. The exterior door 28 need not have a close fit with its frame as any leakage around this door will go directly into the top passageway 25. The by-pass door 25 need not have a close fit with its frame as the draft pressure differential across this door is low due to the stack efiect' of the passageway 26. Any leakage around this door will therefore be low. Thus, ground joints or gaskets are not necessary with the doors 25 and 28. Any air leaking around the by-pass door 25 will still be contained within the stove. The bypass door protects the exterior door 28 and prevents the formation of condensed tar or other material on the exterior door. Very little tar will form on the by-pass door 25 as this door is maintained quite warm. The location of the exterior door 28 provides adequate visibility and accessibility to the top portion of the stove above the fire box. The two doors also permit ready visibility and accessibility into the fire box itself.

Although the fire box may have either a horizontal or vertical wall !5, it is preferred however that this wall be sharply inclined as shown in Fig. 1. This permits the coal to be fed down more readily as the coal in the bottom of the fire box is burned. With this inclined wall, the operator of the stove is less likely to punch the wall when pushing down coal. Even if the wall is punched, it will only be with a glancing blow. The sloping top wall l'5 also provides for a sharply expanding combustion zone IS. This slows down the velocity of the gases in the top of the stove and results in less fiy-ash being carried up through the stack ll. This construction is also more self-cleaning as any fly-ash deposted on the top of the wall l5 will tend to roll down the wall and back into the combustion space in the fire box.

Although the invention has been described as related to a coal stove, it is obVious that it can also be applied to a urnace, a hot water heater, or the like. The by-pass door and the exterior door may be arranged either horizontally, Vertically, or inclined.

Having described my invention as relating to various embodiments of the same, it is my intention that the invention be not limited by any of the details of description, but rather be construed broadly within its spirit and scope as set out in the accompanying claims.

I claim:

1. In a coal stove and the like including a fire box and means forming a passageway for gases adjacent the top of the fire box, a door in the fire box adjacent the top thereof normally closing an opening between said passageway and the fire box, a second door adjacent the first door normally closing an opening between said passageway and the exterior of the stove, said first door being hingedly mounted on said second door, and single means for opening said first door and said second door.

2. The coal stove of claim 1 wherein means are provided for releasably holding said doors together after the first door has been opened.

JOHN C. MILES.

REFEREN CES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 161186 McKenney Aug. 31, 1875 '745,909 Robischung Dec. 1, 1903 980264 Howard Jan. 3, 1911 l,997,347 Schroeder et al. Apr. 9, 1935 2,174,347 Card Sept. 26, 1939 2,284,464 Wingert May 26, 1942 2,302,197 Edwards Nov. 17, 1942 2348333 Seeley May 16, 1944 2,352,057 Wingert June 20, 1944 2,390,483 Wingert Dec. 4, 1945 2,399,814 Martin May 7, 1946 2,438,123 Lambert et al Mar. 23, 1948 2,443,910 Higley June 22, 1948 2,444,402 Klein June 29, 1948 FOREIGN PATENTS Number Country Date 7,611 Great Britain of 1838 5,165 Great Britain of 1894 

